Checking out the changes to the MLS roster rules for the 2013 season

— First off, the salary cap is now $2.95 million up from $2.81 million. Only players on the senior roster (spots 1-20) count against the cap. Homegrown players, Generations Adidas signings and a lot of minimum-salary guys don’t count against the cap.

— The minimum salary for veterans has been upped to $46,500 from $44,000.

— The minimum for young players, sometimes referred to as “apprentice salaries,” is $35,125, up from $33,750. These players must be under 25.

— Only three designated players are allowed on the roster, that’s no different, but the DP charge is now $368,750 instead of $350,000. Midseason DP signings still count $175,000.

— Young DPs (ages 21-23) count $200,000 and even younger DPs (ages 20 and below) count $150,000, which is essentially the same as last year. Any young DP signed midseason counts $150,000.

— Teams no longer get $35,000 in allocation money for leaving the last two spots on the roster unfilled.

— The primary transfer window is actually open until May 6 this year (it was April 15 last year). The summer transfer window is from July 9 to Aug. 8. Windows mark when teams and league can acquire players registered in other leagues around the world, like current Sounders target Obafemi Martins in Spain.

— The roster freeze is Sept. 13, meaning no more acquisitions, cuts, moves to the disabled list or anything until after MLS Cup. The only exception is a case of extreme hardship (e.g. all your goalkeepers are injured) and that’s up to the discretion of the league.

— Team begin with eight international roster slots, but those can be traded. Seattle, for example, has seven after trading one to Montreal for Lamar Neagle.

— Allocation money is always a bit confusing, but teams accrue it by missing the playoffs, transferring a player outside of MLS for a profit, being an expansion team, qualifying for CONCACAF Champions League and as part of other teams paying a $150,000 surcharge for a third DP slot (something the Sounders have already paid for). Allocation money, which is often used to buy down the cap hit on contracts, can also be acquired in trades. The amounts teams have are never made public.

— DPs can be bought down to a $150,000 cap hit with allocation money.

— Players with contracts that aren’t fully guaranteed can be waived before July 1 to open up cap space.

— I hope this helps, and let me know if something looks wrong (it was a lot of back and forth with the 2012 and 2013 rules). Check out the link for more information on things like right of first refusal (e.g. teams retains rights to unsigned college players for two years), weighted lotteries, the allocation order, injured list rules, waivers, the Re-Entry Process, contract buyouts and more.